The present invention relates to an active matrix type liquid crystal display apparatus.
Recently, the liquid crystal display apparatus is being applied as a display mainly composed of the motion picture such as a liquid crystal TV. However, the deterioration of the picture quality of the motion picture (hereafter, motion picture quality) in the liquid crystal display apparatus is reported at Institute of Telecommunications Engineers technical report EID96-4, pp.19-26(1996-06), etc.
According to this, the motion picture is to deteriorate because the liquid crystal display is a holding luminescence type display, and growing dim is generated in the moving image by the disagreement of the moving image to which the holding luminescence is done and the glance movement by man""s motion picture follow seeing. In order to improve the deterioration in the quality of this motion picture, the method of making the frame frequency n times speed. The method of making the image display 1/n frame period and setting the period of the remainder to be a blanking display has been also described. Where, the larger the numerical value of n, the more it is effective to the motion picture which moves at a high speed.
A method of improving the quality of the motion picture is described, for example, in the Japanese Patent Application Laid-open No. 11-109921. According to the Official Gazette, the signal line drive circuits are provided at the upper part and the bottom part of the liquid crystal panel, the scanning line is selected twice while one screen is displayed, the display image writing and the blanking image writing is performed by using the upper and the lower signal line drive circuit, respectively, and about the half of one screen period is used for the image display and the remaining half for a blanking display.
However, the parts cost is high because expensive signal line drive circuits are used at both the upper part and the bottom part of the liquid crystal panel in the method disclosed in Japanese Patent Application Laid-open No. 11-109921, and thus the liquid crystal display also becomes expensive.
Moreover, when the display speed of the motion picture (movement speed on the screen) is fast, the improvement effect of the display characteristic is insufficient in the method of setting half one screen cycle to be a blanking display like this prior art.
An object of the present invention is to provide the liquid crystal display which obtains an excellent display characteristic even when the motion picture is displayed.
The feature according to one embodiment of the liquid crystal display of the present invention resides in that a liquid crystal display apparatus comprising: a pair of substrates, at least one of which is transparent; a liquid crystal layer interposed between said pair of substrates; a plurality of scanning electrode lines and a plurality of signal electrode lines formed so as to cross each other in a matrix form; active elements, each formed proximate to each of the crossing points of said corresponding signal lines and said scanning lines, pixel electrodes connected to said active elements, common lines formed between each of said scanning lines, and opposed electrodes, each formed between said pixel electrodes and each connected to said common lines, are arranged on one of said pair of substrates; said liquid crystal display apparatus displaying with moving the liquid crystal molecule in the liquid crystal layer by the voltage applied to said pixel electrodes and said opposed electrodes. The apparatus further comprising: a plurality of second active elements connected to said plural opposed electrodes, said plural pixel electrodes corresponding to the opposed electrodes, and second scanning lines different from said scanning lines connected through said active elements to the pixel electrodes, and wherein common lines corresponding to said pixel electrodes are selected between the selection pulse of the scanning line to write the picture signal in said pixel electrode and the selection pulse of said scanning line to display the following images and a pulse to clear the picture signal applied to said pixel electrode is applied.
Further, such a liquid crystal display has a display mode of a normally black characteristic in which the black is displayed when a voltage is not applied to the liquid crystal.